Second international consensus report on gaps and opportunities for the clinical translation of precision diabetes medicine

Precision medicine is part of the logical evolution of contemporary evidence-based medicine that seeks to reduce errors and optimize outcomes when making medical decisions and health recommendations. Diabetes affects hundreds of millions of people worldwide, many of whom will develop life-threatening complications and die prematurely. Precision medicine can potentially address this enormous problem by accounting for heterogeneity in the etiology, clinical presentation and pathogenesis of common forms of diabetes and risks of complications. This second international consensus report on precision diabetes medicine summarizes the findings from a systematic evidence review across the key pillars of precision medicine (prevention, diagnosis, treatment, prognosis) in four recognized forms of diabetes (monogenic, gestational, type 1, type 2). These reviews address key questions about the translation of precision medicine research into practice. Although not complete, owing to the vast literature on this topic, they revealed opportunities for the immediate or near-term clinical implementation of precision diabetes medicine; furthermore, we expose important gaps in knowledge, focusing on the need to obtain new clinically relevant evidence. Gaps include the need for common standards for clinical readiness, including consideration of cost-effectiveness, health equity, predictive accuracy, liability and accessibility. Key milestones are outlined for the broad clinical implementation of precision diabetes medicine.

Australian primary health care nurses

Preconception care (PCC) entails counselling and interventions to optimise health before pregnancy. Barriers to this service delivery include access and time. Primary healthcare nurses (PHCNs) are uniquely placed to deliver PCC. The aim of this study was to understand PHCNs' knowledge, practice and attitudes to PCC. A cross-sectional study was performed of a convenience sample of PHCNs in Australia who were seeing people of reproductive age. Recruitment was via the Australian Primary Health Care Nurses Association (APNA) electronic communication platforms. The 18-item, online, anonymous survey captured demographics, as well as PCC knowledge, practices and attitudes. Descriptive statistics were used to describe our findings. In all, 152 completed surveys were received. Of all respondents, 74% stated they discuss PCC in their practice, although only 13% do so routinely. Of these, more preconception discussions are held with women than with men. In total, 95% of respondents identified at least one barrier to delivery of PCC, with lack of time and knowledge being the most common. The findings of this study can inform targeted strategies, including education programs and resources, and consideration of incentives to support PHCNs deliver PCC. This study identifies areas for improvement at the individual, organisational and health system levels to enhance the role of PHCNs in PCC.

Concordance between a neuroradiologist, a consultant radiologist and trained reporting radiographers interpreting MRI head examinations: An empirical study

INTRODUCTION

This study assessed agreement between MRI reporting radiographers and a consultant radiologist compared with an index neuroradiologist when reporting MRI head (brain/internal auditory meati [IAMs]) examinations. The effect on patient management of any discordant reports was also examined.

METHODS

Two trained MRI reporting radiographers (RRs), a consultant radiologist (CR) and an index neuroradiologist (INR) reported on a random sample of 210 MRI examinations. The radiographers reported during clinical practice and the radiologists in clinical practice conditions. Two independent consultant physicians (neuro-rehabilitation and neuropsychiatry) compared these reports with the index neuroradiologist report for agreement and the clinical importance of discrepant reports.

RESULTS

Overall observer agreement between the RRs and CR was comparable in relation to agreement with the INR: RR; 93/210 (44.3%); and the CR; 83/210 (39.4%) for all head MRI examinations (p = 0.32). For brain examinations the difference was similar: RR; 64/180 (35.6%); and CR; 54/190 (30.0%), p = 0.26. Agreement rates for the IAMs examinations were identical, 29/30 (97.7%). For all head MRI examinations (n = 210) there was a very small observed difference of <0.5% in mean agreement between the reporting radiographers and the consultant radiologist (p = 0.92) for examinations where a major disagreement would have been likely to have led to a change in patient management.

CONCLUSION

MRI reporting radiographers reported during clinical practice on MRI head examinations to a level of agreement comparable with a consultant radiologist.

IMPLICATIONS FOR PRACTICE

This is an area in which radiographers could provide additional reporting roles to the reporting service to increase capacity. Wider potential benefits include cost-effectiveness and role development/retention of radiographers.

Towards antigen-specific Tregs for type 1 diabetes: Construction and functional assessment of pancreatic endocrine marker, HPi2-based chimeric antigen receptor

Type 1 Diabetes (T1D) is an autoimmune disease marked by direct elimination of insulin-producing β cells by autoreactive T effectors. Recent T1D clinical trials utilizing autologous Tregs transfers to restore immune balance and improve disease has prompted us to design a novel Tregs-based antigen-specific T1D immunotherapy. We engineered a Chimeric Antigen Receptor (CAR) expressing a single-chain Fv recognizing the human pancreatic endocrine marker, HPi2. Human T cells, transduced with the resultant HPi2-CAR, proliferated and amplified Granzyme B accumulation when co-cultured with human, but not mouse β cells. Furthermore, following exposure of HPi2-CAR transduced cells to islets, CD8⁺ lymphocytes demonstrated enhanced CD107a (LAMP-1) expression, while CD4⁺ cells produced increased levels of IL-2. HPi2-CAR Tregs failed to maintain expansion due to a persistent tonic signaling from the CAR engagement to unexpectantly HPi2 antigen present on Tregs. Overall, we show lack of functionality of HPi2-CAR and highlight the importance of careful selection of CAR recognition driver for the sustainable activity and expandability of engineered T cells.

0280 Change in Sleep Depth Across the Night as a Measure of Sleep Adequacy

Introduction

It is well known that sleep becomes lighter towards the end of the night reflecting the reduction in homeostatic sleep pressure. We hypothesized that more adequate nocturnal sleep (i.e. sufficient quantity and quality for the individual) would result in a greater reduction in sleep depth across the night and would be reflected in decreased next-day sleep tendency.

Methods

In a secondary analysis of data from a study in which sleep depth was altered by sleep restriction combined with either placebo or gaboxadol (a delta-promoting drug) we correlated change across the night in two measures of sleep depth with next-day Multiple Sleep Latency Test (MSLT) latencies. Forty-one healthy subjects underwent 8 consecutive sleep studies; two baseline, four sleep restriction (5 hours) and two recovery nights. MSLT was performed following each baseline night and the last two restriction nights. Sleep depth in the first and last hours of NREM sleep was determined by two

methods

1) Log delta spectral power; 2) The odds-ratio-product (ORP), a recently introduced continuous measure of sleep depth. The difference between initial and final values was calculated (ΔDelta, ΔORP). Post-restriction MSLT latency was correlated with baseline MSLT latency, ΔDelta, ΔORP, log delta power and ORP in the last hour, lost total sleep time and lost REM time.

Results

ΔDelta was -0.27 ±0.13 and ΔORP was 0.17 ±0.13, both changes reflecting lightening of sleep across the night. In both univariate and multivariate analysis only baseline MSLT latency (p &lt 0.001) and ΔORP (p &lt 0.01) were significantly and positively correlated with post-restriction MSLT latency.

Conclusion

The reduction in sleep depth across the night as measured by ORP, but not by delta power, is significantly correlated with reduced objective sleepiness following sleep restriction. ΔORP may be a useful index that reflects sleep adequacy during the night.

Support

None

0150 Comparing Two Measures of Sleep Depth/ Intensity

Introduction

There is currently no well-validated method for evaluating objective sleep depth/intensity. Delta power is thought to reflect sleep depth based upon limited evidence. Odds-ratio-product (ORP) is a recently introduced continuous measure of sleep depth. We compared delta spectral power (delta) and ORP as measures of sleep depth/intensity during manipulations that altered sleep depth (sleep restriction with placebo or with a delta-promoting drug). We hypothesized that ORP will provide a more robust measure of sleep depth.

Methods

This is a secondary analysis of data from a study in which forty-one healthy subjects were sleep restricted and randomized to receive placebo or gaboxadol 15mg. Participants underwent consecutive in-laboratory sleep studies on two baseline, four sleep restriction (5 hours) and two recovery nights. The relation between delta or ORP during any given 30s epoch and sleep depth, operationally defined as the probability of arousal / awakening occurring during the next 30 seconds (arousability), was assessed.

Results

Mean ORP values differed significantly among the four sleep / wake stages, but delta power did not differentiate wake, N1 and N2. The relation between ORP and arousability was linear across the entire range of ORP whereas delta power detected differences in arousability only with delta values &lt 300 μV2. Correlations with arousability in individual subjects were stronger with ORP (p &lt 0.0001). Receiver operating characteristic analysis found the ability to predict imminent arousal to be significantly greater with ORP than with delta power for all experimental conditions (p &lt 0.0001). The increase in sleep depth with restriction alone was detected on the second day of restriction by ORP (p &lt 0.01) but not by delta.

Conclusion

As compared to delta power, ORP is more discriminating among sleep stages, more sensitive to sleep restriction, and more closely associated with arousability. These observations indicate ORP better reflects sleep depth/intensity.

Support

None

Identifying physiological measures of lifetime welfare status in pigs: exploring the usefulness of haptoglobin, C- reactive protein and hair cortisol sampled at the time of slaughter

BACKGROUND

Physiological measures indicative of the welfare status of animals during rearing could form part of an abattoir-based animal health and welfare assessment tool. A total of 66 pigs were used in this study, the aim of which was to assess how serum concentrations of haptoglobin (Hp) and C-reactive protein (CRP) (assessed in 51 pigs), and hair concentrations of cortisol (assessed in 65 pigs), measured at or close to slaughter, reflected welfare-related indicators recorded from the animal during its lifetime. These indicators were recorded at intervals between 7 and 21 weeks of age and included assigning scores for levels of tail and skin lesions, recording the presence or absence of certain health issues, and conducting qualitative behavioural assessments (QBA).

RESULTS

Pigs recorded as having tail lesions during their lifetime had higher hair cortisol levels than those with no tail lesions (tail lesions: 47.87 ± 3.34 pg/mg, no tail lesions: 42.20 ± 3.29 pg/mg, P = 0.023), and pigs recorded as having moderate or severe tail lesions had higher Hp levels than those with no or mild tail lesions (moderate/severe: 1.711 mg/ml ± 0.74, none/mild: 0.731 mg/ml ±0.10, P = 0.010). Pigs recorded as being lame during their lifetime tended to have higher hair cortisol levels than non-lame pigs (lame: 52.72 pg/mg ± 3.83, not lame: 43.07 pg/mg ± 2.69, P = 0.062). QBA scores were not associated with any of the physiological measures (P > 0.05). Receiver Operator Curve (ROC) analysis was also carried out to get a better understanding of the usefulness of the physiological measures in discriminating animals that had had welfare-related issues recorded during their lifetime from those that had not. Hair cortisol was determined as having 'moderate' accuracy in discriminating pigs that were tail bitten on-farm from unbitten pigs (AUC: 0.748) while Hp and CRP were determined to have no meaningful discriminatory ability (AUC < 0.600).

CONCLUSION

This research should be repeated on a larger scale, but the results suggest that hair cortisol measured at slaughter could provide insight into the welfare status of pigs during their lifetime. Hp may be a useful indicator of tail lesions in pigs. However, further research utilising a greater proportion of severely bitten pigs is required before conclusions can be drawn.

A Coccidioides posadasii CPS1 Deletion Mutant Is Avirulent and Protects Mice from Lethal Infection

The CPS1 gene was identified as a virulence factor in the maize pathogen Cochliobolus heterostrophus Hypothesizing that the homologous gene in Coccidioides posadasii could be important for virulence, we created a Δcps1 deletion mutant which was unable to cause disease in three strains of mice (C57BL/6, BALB/c, or the severely immunodeficient NOD-scid,γc(null) [NSG]). Only a single colony was recovered from 1 of 60 C57BL/6 mice following intranasal infections of up to 4,400 spores. Following administration of very high doses (10,000 to 2.5 × 10(7) spores) to NSG and BALB/c mice, spherules were observed in lung sections at time points from day 3 to day 10 postinfection, but nearly all appeared degraded with infrequent endosporulation. Although the role of CPS1 in virulence is not understood, phenotypic alterations and transcription differences of at least 33 genes in the Δcps1 strain versus C. posadasii is consistent with both metabolic and regulatory functions for the gene. The in vitro phenotype of the Δcps1 strain showed slower growth of mycelia with delayed and lower spore production than C. posadasii, and in vitro spherules were smaller. Vaccination of C57BL/6 or BALB/c mice with live Δcps1 spores either intranasally, intraperitoneally, or subcutaneously resulted in over 95% survival with mean residual lung fungal burdens of <1,000 CFU from an otherwise lethal C. posadasii intranasal infection. Considering its apparently complete attenuation of virulence and the high degree of resistance to C. posadasii infection when used as a vaccine, the Δcps1 strain is a promising vaccine candidate for preventing coccidioidomycosis in humans or other animals.

Cardiovascular risk in patients with small and medium abdominal aortic aneurysms, and no history of cardiovascular disease

Background

Cardiovascular disease (CVD) is the main cause of death in people with abdominal aortic aneurysm (AAA). There is little evidence that screening for AAA reduces all-cause or cardiovascular mortality. The aim of the study was to assess whether subjects with a small or medium AAA (3·0–5·4 cm), without previous history of clinical CVD, had raised levels of CVD biomarkers or increased total mortality.

Methods

This prospective study included subjects with a small or medium AAA and controls, all without a history of clinical CVD. CVD biomarkers (high-sensitivity C-reactive protein, hs-CRP; heart-type fatty acid-binding protein, H-FABP) were measured, and survival was recorded.

Results

Of a total of 815 people, 476 with an AAA and 339 controls, a cohort of 86 with small or medium AAA (3–5·4 cm) and 158 controls, all with no clinical history of CVD, were identified. The groups were matched for age and sex. The AAA group had higher median (i.q.r.) levels of hs-CRP (2·8 (1·2–6·0) versus 1·3 (0·5–3·5) mg/l; P &lt; 0·001) and H-FABP (4·6 (3·5–6·0) versus 4·0 (3·3–5·1) µg/l; P = 0·011) than controls. Smoking was more common in the AAA group; however, hs-CRP and H-FABP levels were not related to smoking. Mean survival was lower in the AAA group: 6·3 (95 per cent confidence interval (c·i.) 5·6 to 6·9) years versus 8·0 (7·6 to 8·1) years in controls (P &lt; 0·001). Adjusted mortality was higher in the AAA group (hazard ratio 3·41, 95 per cent c·i. 2·11 to 9·19; P &lt; 0·001).

Conclusion

People with small or medium AAA and no clinical symptoms of CVD have higher levels of hs-CRP and H-FABP, and higher mortality compared with controls. They should continue to receive secondary prevention against CVD.

Sleep, glucose, and daytime functioning in youth with type 1 diabetes

STUDY HYPOTHESES: 1) Youth with evidence of SDB (total apnea-hypopnea index [Total-AHI] ≥ 1.5) would have significantly worse glucose control than those without SDB; 2) Elevated self-reported sleepiness in youth with T1DM would be related to compromised psychosocial functioning; and 3) Youth with T1DM would have significantly less slow wave sleep (SWS) than controls.

DESIGN

The study utilized home-based polysomnography, actigraphy, and questionnaires to assess sleep, and continuous glucose monitors and hemoglobin A1C (HbA1C) values to assess glucose control in youth with T1DM. We compared sleep of youth with T1DM to sleep of a matched control sample.

SETTING

Diabetic participants were recruited in a pediatric endocrinology clinic.

PARTICIPANTS

Participants were youth (10 through 16 years) with T1DM. Controls, matched for sex, age, and BMI percentile, were from the Tucson Children's Assessment of Sleep Apnea study.

RESULTS

Participants with a Total-AHI ≥ 1.5 had higher glucose levels. Sleepiness and/or poor sleep habits correlated with reduced quality of life, depressed mood, lower grades, and lower state standardized reading scores. Diabetic youth spent more time (%) in stage N2 and less time in stage N3. Findings related to sleep architecture included associations between reduced SWS and higher HbA1C, worse quality of life, and sleepiness. More time (%) spent in stage N2 related to higher glucose levels/hyperglycemia, behavioral difficulties, reduced quality of life, lower grades, depression, sleep-wake behavior problems, poor sleep quality, sleepiness, and lower state standardized math scores.

Adrenal hyperplasia and adenomas are associated with inhibition of phosphodiesterase 11A in carriers of PDE11A sequence variants that are frequent in the population

Several types of adrenocortical tumors that lead to Cushing syndrome may be caused by aberrant cyclic AMP (cAMP) signaling. We recently identified patients with micronodular adrenocortical hyperplasia who were carriers of inactivating mutations in the 2q-located phosphodiesterase 11A (PDE11A) gene. We now studied the frequency of two missense substitutions, R804H and R867G, in conserved regions of the enzyme in several sets of normal controls, including 745 individuals enrolled in a longitudinal cohort study, the New York Cancer Project. In the latter, we also screened for the presence of the previously identified PDE11A nonsense mutations. R804H and R867G were frequent among patients with adrenocortical tumors; although statistical significance was not reached, these variants affected significantly enzymatic function in vitro with variable increases in cAMP and/or cyclic guanosine 3',5'-monophosphate levels in HeLa and HEK293 cells. Adrenocortical tissues carrying the R804H mutation showed 2q allelic losses and higher cyclic nucleotide levels and cAMP-responsive element binding protein phosphorylation. We conclude that missense mutations of the PDE11A gene that affect enzymatic activity in vitro are present in the general population; protein-truncating PDE11A mutations may also contribute to a predisposition to other tumors, in addition to their association with adrenocortical hyperplasia. We speculate that PDE11A genetic defects may be associated with adrenal pathology in a wider than previously suspected clinical spectrum that includes asymptomatic individuals.

Cyclical Cushing syndrome presenting in infancy: an early form of primary pigmented nodular adrenocortical disease, or a new entity?

Cushing syndrome is uncommon in childhood and rare in infancy. We report the case of a 3-yr-old child who presented with symptoms of Cushing syndrome beginning shortly after birth. Her hypercortisolemia was cyclical, causing relapsing and remitting symptoms, which eventually led to suspicions of possible Munchausen syndrome by proxy. Investigation at the National Institutes of Health excluded exogenous administration of glucocorticoids and indicated ACTH-independent Cushing syndrome. Paradoxical response to dexamethasone stimulation (Liddle's test) suggested a diagnosis of primary pigmented nodular adrenocortical disease (PPNAD). After bilateral adrenalectomy, both glands showed micronodular adrenocortical hyperplasia, but histology was not consistent with typical PPNAD. DNA analysis of the coding sequences of the PRKAR1A gene (associated with PPNAD and Carney complex) and the GNAS gene (associated with McCune-Albright syndrome) showed no mutations. We conclude that hypercortisolemia in infancy may be caused by micronodular adrenocortical hyperplasia, which can be cyclical and confused with exogenous Cushing syndrome. A paradoxical rise of glucocorticoid excretion during Liddle's test may delineate these patients. Infantile micronodular disease has some features of PPNAD and may represent its early form; however, at least in the case of the patient reported here, micronodular hyperplasia was not caused by coding mutations of the PRKAR1A or GNAS genes or associated with typical histology or any other features of Carney complex or McCune-Albright syndrome and may represent a distinct entity.

An RGD sequence in the P2Y(2) receptor interacts with alpha(V)beta(3) integrins and is required for G(o)-mediated signal transduction

The P2Y(2) nucleotide receptor (P2Y(2)R) contains the integrin-binding domain arginine-glycine-aspartic acid (RGD) in its first extracellular loop, raising the possibility that this G protein-coupled receptor interacts directly with an integrin. Binding of a peptide corresponding to the first extracellular loop of the P2Y(2)R to K562 erythroleukemia cells was inhibited by antibodies against alpha(V)beta(3)/beta(5) integrins and the integrin-associated thrombospondin receptor, CD47. Immunofluorescence of cells transfected with epitope-tagged P2Y(2)Rs indicated that alpha(V) integrins colocalized 10-fold better with the wild-type P2Y(2)R than with a mutant P2Y(2)R in which the RGD sequence was replaced with RGE. Compared with the wild-type P2Y(2)R, the RGE mutant required 1,000-fold higher agonist concentrations to phosphorylate focal adhesion kinase, activate extracellular signal-regulated kinases, and initiate the PLC-dependent mobilization of intracellular Ca(2+). Furthermore, an anti-alpha(V) integrin antibody partially inhibited these signaling events mediated by the wild-type P2Y(2)R. Pertussis toxin, an inhibitor of G(i/o) proteins, partially inhibited Ca(2+) mobilization mediated by the wild-type P2Y(2)R, but not by the RGE mutant, suggesting that the RGD sequence is required for P2Y(2)R-mediated activation of G(o), but not G(q). Since CD47 has been shown to associate directly with G(i/o) family proteins, these results suggest that interactions between P2Y(2)Rs, integrins, and CD47 may be important for coupling the P2Y(2)R to G(o).

Foot problems in patients with systemic sclerosis

OBJECTIVES

To assess the nature of the foot problems experienced in patients with systemic sclerosis (SSc) and patient awareness of such problems.

METHODS

Fifty unselected patients (42 females, eight males) with SSc were assessed by means of examination by a senior podiatrist, completion of a questionnaire detailing past and present foot problems, determination of random plasma glucose, plain X-rays of the feet, and measurement of the ankle/brachial index and of digital pulses by Doppler ultrasound.

RESULTS

Eighty-six per cent of patients reported colour changes in their feet in response to temperature changes, 82% reported pain usually related to cold, 26% had suffered foot ulceration and 8% had a history of foot surgery. Podiatry assessment confirmed the presence of significant abnormalities, including ulcerations in 10%, pre-ulcerative lesions in 34%, toenail changes in 62%, callus formation in 80% and calcinosis in 18%. Forty per cent of the patients had problems with the fitting of shoes, and 19% had been provided with footwear from the hospital. Plain films of the feet demonstrated the presence of erosions in 6%, soft-tissue calcification in 17%, osteopenia in 26% and degenerative changes in 60% of cases. Ten per cent of the patients had an abnormal ankle brachial index (less than 1.0). Only 21% of the 47 patients in whom digital pulses were examined had normal pulses in all toes, and in 26% all toe pulses were absent.

CONCLUSION

Although problems with the hands are well recognized in SSc, foot problems also occur in the majority of patients, and can be a cause of major disability. Care of the feet is therefore an important part of the management of SSC.

Overlapping expression of zebrafish T-brain-1 and eomesodermin during forebrain development

T-box transcription factors are important determinants of embryonic cell fate and behaviour. Two T-box genes are expressed in the developing telencephalon of several vertebrate species, including amphibia, birds and mammals. Here we report the cloning of zebrafish T-brain-1 (tbr1) and eomesodermin (eom). As a prelude to genetic studies of neuro-ectodermal fate determination we studied their expression pattern during embryogenesis and early larval development. Eom is expressed in the presumptive telencephalon from around the 4-5 somite stage in bilaterally symmetric groups of cells; the number of positive cells increases dramatically with time and encompasses the entire dorsal telencephalon by the 22 somite stage. Tbr1 is expressed from the 18 somite stage in a subset of eom-expressing cells. By 24 hpf eom and tbr1 are expressed in largely overlapping domains in the dorsal telencephalon, tbr1 is expressed in postmitotic cells whereas eomes is also expressed in proliferative ventricular zone cells. Both genes are also found in a small domain of the diencephalon bordering the telencephalon. A detailed analysis of the expression of tbr1 and eom in the brain of 4 day old larvae shows that the two T-box genes are differentially expressed in various cell populations of the developing brain.

Stabilisation of Salmonella vaccine vectors by the induction of trehalose biosynthesis

The growth of an aroA mutant of Salmonella typhimurium (SL3261) in minimal medium containing 0.5 M NaCl resulted in the intracellular accumulation of 2.2 micromol trehalose/mg total protein. The vacuum drying of these bacteria in the presence of trehalose allowed the recovery of 35% of the viable cells that were present before drying. In contrast, bacteria cultured in control medium accumulated 0.4 micromol trehalose/mg total protein and only 5% of the viable cells were recovered after vacuum drying with trehalose. Similar results were obtained when S. typhimurium SL3261, expressing the vaccine antigen (F1-antigen) of Yersinia pestis, was cultured in minimal medium with or without 0.5 M NaCl and dried in the presence of trehalose. Although these results indicate the potential for trehalose stabilisation of vaccine strains of S. typhimiurium, growth in minimal medium containing 0.5 M NaCl resulted in the loss of invasion competence of the bacteria.

Ace/Fgf8 is required for forebrain commissure formation and patterning of the telencephalon

Fibroblast growth factors (Fgfs) form a large family of secreted signalling proteins that have a wide variety of roles during embryonic development. Within the central nervous system (CNS) Fgf8 is implicated in patterning neural tissue adjacent to the midbrain-hindbrain boundary. However, the roles of Fgfs in CNS tissue rostral to the midbrain are less clear. Here we examine the patterning of the forebrain in zebrafish embryos that lack functional Fgf8/Ace. We find that Ace is required for the development of midline structures in the forebrain. In the absence of Ace activity, midline cells fail to adopt their normal morphology and exhibit altered patterns of gene expression. This disruption to midline tissue leads to severe commissural axon pathway defects, including misprojections from the eye to ectopic ipsilateral and contralateral targets. Ace is also required for the differentiation of the basal telencephalon and several populations of putative telencephalic neurons but not for overall regional patterning of forebrain derivatives. Finally, we show that ace expression co-localises with anterior neural plate cells that have previously been shown to have forebrain patterning activity. Removal of these cells leads to a failure in induction of ace expression indicating that loss of Ace activity may contribute to the phenotypes observed when anterior neural plate cells are ablated. However, as ace mutant neural plate cells still retain at least some inductive activity, then other signals must also be produced by the anterior margin of the neural plate.

A double-blind placebo-controlled trial of antioxidant therapy in limited cutaneous systemic sclerosis

OBJECTIVE

To evaluate the effects of a combination of micronutrient antioxidants (selenium, beta-carotene, vitamin C, vitamin E and methionine) with allopurinol in patients with limited cutaneous systemic sclerosis (SSc).

METHODS

The study was designed as a placebo-controlled double-blind crossover study. A carryover effect was detected retrospectively for some of the prescribed antioxidants, and so the data were analysed as: (a) a between group comparison of the first 10 week treatment period; and (b) a within group comparison of the first and second 10-week periods in those who received placebo treatment first. Study end-points were plasma von Willebrand factor (vWF), thermographic response to a standard cold challenge, frequency and duration of Raynaud's attacks, patient opinion, and specialised biochemical parameters (fatty acid profiles, antioxidants and markers of free radical injury).

RESULTS

Thirty-three patients were recruited. The median duration of Raynaud's phenomenon was 10 years (range 2 to 50 years) in the active-first group and 10 years (range 4 to 53 years) in the placebo-first group. In the 10-week study, there were no differences between the active and placebo groups in the change from baseline for vWF, for the parameters of the rewarming curve, or for patients' symptoms. Despite a rise in circulating antioxidant levels, there was no fall in markers of free radical mediated injury. In the 20-week cross-over study, patients did not experience any clinical benefit from active treatment compared to placebo.

CONCLUSION

No clinical benefit could be demonstrated from active treatment. There are several possible explanations for this negative result, including the short duration of therapy. It is possible that antioxidant therapy, to be effective, needs to be given early in the SSc disease process, before the onset of irreversible tissue damage.

Renal injury and salt-sensitive hypertension after exposure to catecholamines

We investigated whether chronic infusion of phenylephrine could induce structural and functional changes in the kidney of rats with the subsequent development of salt-sensitive hypertension. Rats were infused with phenylephrine (0.15 mmol/kg per day) by minipump, resulting in a moderate increase in systolic blood pressure (BP) (17 to 25 mm Hg) and a marked increase in BP variability as measured by an internal telemetry device. After 8 weeks, the phenylephrine infusion was stopped with the return of BP to normal, and a nephrectomy was performed for histological studies. Glomeruli were largely spared, but focal tubulointerstitial fibrosis was present, with the de novo expression of osteopontin by injured tubules, macrophage and "myofibroblast" accumulation, and focal increases in mRNA for transforming growth factor beta by in situ hybridization. Peritubular capillaries at sites of injury had distorted morphology with shrinkage, rounding, and focal rarefaction, and endothelial cell proliferation was also identified. Rats were randomized to a high (8% NaCl or 1.36 mol/kg) or low (0.1% NaCl or 17 mmol/kg) salt diet. After 4 to 8 weeks, phenylephrine-treated rats on a high salt diet developed marked hypertension, which was in contrast with phenylephrine-treated rats placed on a low salt diet or vehicle-treated rats given a high salt diet. Hypertension after phenylephrine exposure correlated with the initial mean systolic BP (r(2)=0.99) and the degree of BP lability (r(2)=0.99) during the phenylephrine infusion, the amount of osteopontin expressed in the initial biopsy/nephrectomy (r(2)=0.74), and the final glomerular filtration rate (r(2)=0.58). These studies provide a mechanism by which a markedly elevated sympathetic nervous system can induce salt-dependent hypertension even when the hyperactive sympathetic state is no longer engaged.

"Nothing about me, without me": participatory action research with self-help/mutual aid organizations for psychiatric consumer/survivors

Participatory action research with self-help/mutual aid organizations for psychiatric consumer/survivors is reviewed. We begin by tracing the origins of and defining both participatory action research and self-help/mutual aid. In so doing, the degree of correspondence between the assumptions/values of participatory action research and those of self-help/mutual aid for psychiatric consumer/survivors is examined. We argue that participatory action research and self-help/mutual aid share four values in common: (a) empowerment, (b) supportive relationships, (c) social change, and (d) learning as an ongoing process. Next, selected examples of participatory action research with psychiatric consumer/survivor-controlled self-help/mutual aid organizations which illustrate these shared values are provided. We conclude with recommendations of how the key values can be promoted in both the methodological and substantive aspects of future participatory action research with self-help/mutual aid organizations for psychiatric consumer/survivors.

Goal-directed transesophageal echocardiography performed by intensivists to assess left ventricular function: comparison with pulmonary artery catheterization

OBJECTIVES

Transesophageal echocardiography (TEE) is a valuable procedure for assessing left ventricular (LV) function, but it has not been widely applied in critical care because of the limited number of intensivists who are trained in echocardiography. This prospective study was designed to evaluate the feasibility of training intensivists to perform a goal-directed, limited-scope TEE to assess LV function in critically ill patients using a pediatric monoplane TEE probe. A secondary goal was to compare the usefulness of the TEE data with that of data obtained by a simultaneous pulmonary artery catheter (PAC).

DESIGN

Prospective, blinded.

SETTING

University teaching hospital.

PARTICIPANTS

One hundred consecutive, intubated, intensive care unit patients.

INTERVENTIONS

Five surgical intensivists with no previous background in echocardiography were trained under the supervision of two cardiologists to perform limited-scope TEE using a monoplane pediatric probe. One intensivist (A) reviewed the PAC data and recorded a diagnostic impression and therapeutic plan. A second intensivist (B), blinded to the PAC data, then performed TEE to determine cardiac volume, LV wall thickness, and LV global and regional wall motion. Intensivists A and B reviewed the data from both PAC and TEE, and intensivist A then formulated a new diagnosis and therapeutic plan.

MEASUREMENTS AND MAIN RESULTS

Intensivists performed 48 TEE examinations under direct supervision of a cardiologist, and 52 without supervision, but reviewed poststudy. The average duration of TEE was 12 +/- 7 minutes. The intensivists' interpretations of TEE data were deemed correct in 93% of cases for LV wall thickness, 87% for intracardiac volume status, 81% for regional LV wall motion abnormalities, and 77% for global LV function. When the TEE and PAC technologies were compared, it was found that the TEE data disagreed with the PAC evaluation of intracardiac volume in 55% of cases and with the PAC assessment of myocardial function in 39% of cases. The post-PAC therapeutic recommendations were different from the post-TEE therapeutic recommendations in 58% of patients.

CONCLUSIONS

Training intensivists in limited-scope, goal-directed TEE, using a pediatric monoplane probe to evaluate LV function, can be done rapidly and safely, and yield data pertinent to management of critically ill patients even in the early stages of skill acquisition.

Getting kids and keeping them: lesbian motherhood in europe

Summary This article looks at two major issues faced by lesbian mothers in Europe: getting kids and keeping them. The first part focuses on the ways lesbians have children, and in particular the different levels of access to formal insemination services for lesbians in European countries. The second part examines custody issues faced by lesbians with children from previous heterosexual relationships, and those faced by lesbians who have children within a lesbian relationship; and legal recognition of the bond between non-biological parents and their children. The article is based on original research and interviews carried out by the author for the book Lesbian Motherhood in Europe.

Medical planning--casualty treatment times at first and second line

OBJECTIVE

To establish the average time taken to treat a seriously wounded battle casualty at First and Second Line (Role 1 and Role 2) according to the British Army Casualty Treatment Regimes under simulated conditions, and, in doing so, to assess whether British medical facilities are capable of meeting the medical planning directives of the Allied Command Europe Rapid Reaction Corps (ARRC).

DESIGN

A casualty evacuation exercise, using standard ARRC medical planning data, deploying the war establishment of personnel and equipment of an armoured Battle Group Regimental Aid Post (RAP) and an armoured Field Ambulance.

SUBJECTS

200 simulated casualties, using 120 healthy soldiers dressed in expendable clothing and carrying a description of their injuries and clinical status.

MAIN OUTCOME MEASURED

The time taken to treat simulated seriously wounded casualties at Role 1, the RAP and at Role 2, the Field Ambulance Dressing Station (DS).

RESULTS

The mean treatment time at Role 1 was 28 minutes and at Role 2 was 17 minutes.

CONCLUSION

Within the (large) caveat of simulation, as presently configured, the Field Ambulance (DS) is well able to cope with the casualty load expected of it by ARRC medical planners but the RAP of the armoured Battle Group is not.

Thermodilution cardiac output measurement during simultaneous volume infusion through the venous infusion port of the pulmonary artery catheter

OBJECTIVE

To determine the effect on thermodilution cardiac output (TDCO) measurements of continuous volume infusion through the right atrial venous infusion port of the pulmonary artery catheter.

DESIGN

Prospective, blinded, randomly allocated crossover.

SETTING

Surgical intensive care unit in a university hospital.

PARTICIPANTS

Forty-nine hemodynamically stable patients between the ages of 43 and 84 in the intensive care unit and with a pulmonary artery catheter in place.

INTERVENTIONS

Each patient received two room-temperature infusions (250 or 500 mL/hr) of 5% dextrose. Consecutive TDCO measurements were taken during each infusion and during a control period (no infusion). The sequence of infusion rates and control period was randomly determined. At both infusion rates, most patients exhibited a decrease in TDCO measurement of between 0.1 and 3.0 L/min. Although some patients exhibited an increase in measured TDCO, this increase was primarily between 0.1 and 0.5 L/min.

MEASUREMENTS AND MAIN RESULTS

The mean TDCO measurements at infusion rates of 0, 250, and 500 mL/hr were 6.77, 6.49, and 6.47 L/min, respectively. Measured TDCO decreased on volume infusion by 0.3 +/- 0.13 L/min (mean +/- SD, p < 0.02).

CONCLUSION

Rapid continuous infusion of fluid through the venous infusion port of the pulmonary artery catheter significantly limits the accuracy of simultaneous TDCO measurements. Optimally, TDCO measurements should be avoided during rapid volume infusion.

Biochemical analysis of mutant T7 primase/helicase proteins defective in DNA binding, nucleotide hydrolysis, and the coupling of hydrolysis with DNA unwinding

We characterized nine helicase-deficient mutants of bacteriophage T7 helicase-primase protein (4A') prepared by random mutagenesis as reported in the accompanying paper (Rosenberg, A. H., Griffin, K., Washington, M. T., Patel, S. S., and Studier, F. W. (1996) J. Biol. Chem. 271, 26819-26824). Mutants were selected from each of the helicase-conserved motifs for detailed analysis to understand better their function. In agreement with the in vivo results, the mutants were defective in helicase activity but were active in primase function. dTTP hydrolysis, DNA binding, and hexamer formation were examined. Three classes of defective mutants were observed. Group A mutants (E348K, D424N, and S496F), defective in dTTP hydrolysis, lie in motifs 1a, 2, and 4 and are possibly involved in NTP binding/hydrolysis. Group B mutants (R487C and G488D), defective in DNA binding, lie in motif 4 and are responsible directly or indirectly for DNA binding. Group C mutants (G116D, A257T, S345F, and G451E) were not defective in any of the activities except the helicase function. These mutants, scattered throughout the protein, appear defective in coupling dTTPase activity to helicase function. Secondary structural predictions of 4A' and DnaB helicases resemble the known structures of RecA and F1-ATPase enzymes. Alignment shows a striking correlation in the positions of the amino acids that interact with NTP and DNA.